Staplers using wire staples for attaching sheets of paper and other similar materials together are common in corporate, institutional, and educational environments. Manually operated and electrically powered staplers are well known and in widespread use. Exemplary manual staplers are shown in U.S. Pat. Nos. 2,973,519 to Jopp, 4,491,261 to Mitsuhashi, 4,496,091 to Yasuda, 4,506,819 to Rand and 4,927,067 to Leszczak, the disclosures of which are hereby incorporated herein by reference. These staplers are typical of those well known in the art in that they have an anvil-supporting base and a staple-driving stapling assembly mechanically coupled to the base by a fixed hinge. The stapling assembly is typical of those well known in the art in that they include a magazine pivotally mounted to the base for holding a bar of U-shaped staples interconnected in a readily separable manner, and an upper body including a staple ejector for driving successive staples out of the magazine, through sheets of paper, etc. and against the anvil on the base to crimp the legs of the staple and fasten the sheets.
These and other conventional staplers having a mechanically coupled base and stapling assembly share a disadvantage in that they define a throat between the base and stapling assembly that has a fixed depth. The throat depth limits the distance from the edge of a sheet at which at staple may be placed. In other words, because of the fixed hinge attaching the base and stapling assembly, the anvil and staple ejector can reach inwardly only a limited distance from an edge of a sheet, i.e. to the point at which the edge of the sheet reaches an inner portion of the throat near the fixed hinge.
This limitation is undesirable in some stapling situations, e.g. where there is a desire to perform “saddle stitching” staples in the center of the width of an 11 inch high by 17 inch wide sheet of paper to permit a fold producing a booklet measuring approximately 8-½ inches wide by 11 inches high. Similarly, such conventional staplers are inadequate on large-scale projects, e.g. on posterboard or other relatively large scale projects such as student's art displays, on bulletin boards, on corporate or promotional displays, etc., where large-sized sheets are used. The use of large-sized sheets prohibits stapling at certain locations interior to the edges of the sheets using conventional staplers, and limits stapling to portions of the sheets near the edges.
What is needed is a stapler capable of stapling sheets at any desired location, including interior locations of relatively large-scale sheets.